Authorities in Florida are looking for a man they say posted a series of messages on Twitter, threatening to shoot students and put pipe bombs inside some schools in the Orlando area.
The Orlando Sentinel reports officials with the FBI, Orlando police and the Orange County Sheriff's Office don't believe the threats are credible. But they're looking for a 23-year-old transient who's lived in Florida, California, Virginia and Maryland.
Officials say the threats started July 24 and targeted four high schools and a middle school. The posts also encouraged people to "shoot up'' the schools.
Orange County Schools sent messages to parents letting them know about the messages.
FBI Special Agent Amy Pittman says "every investigative lead is being aggressively followed'' to locate the suspect.